Wallace, Alfred Russel, 1823-1913, English naturalist. From his study of comparative biology in Brazil and in the East Indies, he evolved a concept of evolution similar to that of Charles Darwin. Like Darwin, he was greatly influenced by the writings of Malthus and Lyell and based his theories on careful observation. Wallace sent his paper on evolution to Darwin in 1858, and its striking coincidences to Darwin's own theory sparked the older, more cautious naturalist to publish On the Origin of Species the following year (and led Darwin's friends to move quickly to assure that his priority would be recognized). Wallace's especial contribution to the evidence for evolution was in biogeography; he systematized the science and wrote The Geographical Distribution of Animals (2 vol., 1876) and a supplement, Island Life (1881). His research in this field is commemorated in the name Wallace's line. He also assisted H. W. Bates in evolving an early concept of mimicry. Wallace's other works include Contributions to the Theory of Natural Selection (1870), Darwinism (1889), and Social Environment and Moral Progress (1913).